Vojtko R., Klučiar T., Králiková S., Hók J. & Pelech O., 2019: Late Badenian to Quaternary palaeostress evolution of the northeastern part of the Danube Basin and the southwestern slope of the Štiavnica Stratovolcano (Slovakia). Acta Geologica Slovaca, 11, 1, 15–29.

Late Badenian to Quaternary palaeostress evolution of the northeastern part of the Danube Basin and the southwestern slope of the Štiavnica Stratovolcano (Slovakia)

Rastislav Vojtko¹, Tomáš Klučiar¹, Silvia Králiková¹, Jozef Hók¹ & Ondrej Pelech²

¹Department of Geology and Palaeontology, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, SK-842 15 Bratislava, Slovak Republic; rastislav.vojtko@uniba.sk, kluciar1@uniba.sk, silvia.kralikova@uniba.sk, jozef.hok@uniba.sk
²State Geological Institute of Dionýz Štúr, Mlynská dolina 1, SK-817 04 Bratislava, Slovakia; ondrej.pelech@geology.sk

Abstract

The Danube Basin, located among the Eastern Alps, Western Carpathians, and Transdanubian Range, covers northwestern part of the Pannonian Basin. The basin is represented by typical finger-like morphostructures of pre-Cenozoic basement and Neogene sediments. Based on the basin-and-range structure, the area is traditionally divided into five depressions (Blatné, Rišňovce, Komjatice, Želiezovce, and Gabčíkovo-Györ depressions). From the geological point of view, the Danube Basin is infilled by the middle Miocene to Quaternary marine, lacustrine, and alluvial sedimentary sequences. The pre-Cenozoic basement is composed of the Tatric and Veporic units, except southernmost part formed by the tectonic unit of the Transdanubian Range. The eastern part of the basin was influenced by extensive volcanic activity of the Štiavnica Stratovolcano and volcanoes buried below the basin fill during the middle Miocene. Fault-slip analysis was performed in the study area to reveal and discuss the palaeostress field evolution form the Badenian onward. The structural measurements were carried out in outcrops with the following lithostratigraphy: (1) Badenian shallow sea to deltaic deposits; (2) Sarmatian deltaic to alluvial sediments; (3) upper Miocene alluvial sequence; (4) Lower Pleistocene river sediments; (5) Pleistocene loess sequences. Based on the obtained fault-slip data and palaeostress reconstruction, four main palaeostress phases can be distinguished: (1) the oldest Late Badenian to Early Sarmatian phase is characterized by strike-slip tectonic regime with the general orientation of compressional stress axis (σ1) in the N–S direction and perpendicular tension, which dominated at the end of the stage (σ₃); (2) Sarmatian to Early Pannonian strike-slip tectonic regime is defined by the NE–SW oriented σ₁ and the NW–SE oriented σ₃; (3) the Pannonian to earliest Pliocene phase can be described by extensional tectonic regime with the orientation of σ₃ in NW–SE direction; (4) the youngest recorded extensional tectonic regime is characterized by the NE–SW to E–W orientation of the σ₃ axis. This tectonic phase can be tenuously dated at Pliocene to Quaternary age and is most probably still active.

Key words: Danube Basin, Štiavnica Stratovolcano, Miocene–Quaternary, tectonic evolution, fault-slip analysis

Manuscript received: 2018-02-23

Revised version accepted: 2019-06-24